Hello, I have written some drivers for the ASpeed AST2400/2500 chips. These chips are designed to be used as BMCs and the core reason for these drivers has been to introduce a communication channel between two processors. The mailbox registers are the channel through which the two processors can communicate, it is worth noting here that the mailbox driver is designed to be flexible enough do allow userspace to arbitrarily write to one or all or a subset of the mailbox registers. This is important as the ASpeed chip allows for enabling hardware interrupts based on writes at a per data register level. It is possible that the other processor will enable interrupts on one of the data registers, as such, the ASpeed end of the protocol will need to be able to treat that register specially. The first intended use of a communication protocol between the ASpeed and the other processor is so they can arbitrate on board flash chip access. The goal is to have the ASpeed chip perform the reads and writes to the flash and present to the other processor in an area of its RAM across a shared bus. Currently the other processor has the flash mapped directly on the shared bus. The LPC bus controlling driver provides a way for the ASpeed userspace to control the mapping across the LPC bus between the ASpeed and the other processor. The RAM region that the LPC control driver will use should be specified in the device tree. Cyril Bur (4): Documentation: dt: mailbox: Add Aspeed ast2400/2500 bindings Documentation: dt: misc: Add Aspeed ast2400/2500 LPC Control bindings drivers/misc: Add ASpeed LPC control driver drivers/mailbox: Add ASpeed mailbox driver .../devicetree/bindings/mailbox/aspeed-mbox.txt | 44 +++ .../devicetree/bindings/misc/aspeed-lpc-ctrl.txt | 78 +++++ drivers/mailbox/Kconfig | 9 + drivers/mailbox/Makefile | 2 + drivers/mailbox/aspeed-mbox.c | 334 +++++++++++++++++++++ drivers/misc/Kconfig | 9 + drivers/misc/Makefile | 1 + drivers/misc/aspeed-lpc-ctrl.c | 269 +++++++++++++++++ include/uapi/linux/aspeed-lpc-ctrl.h | 25 ++ 9 files changed, 771 insertions(+) create mode 100644 Documentation/devicetree/bindings/mailbox/aspeed-mbox.txt create mode 100644 Documentation/devicetree/bindings/misc/aspeed-lpc-ctrl.txt create mode 100644 drivers/mailbox/aspeed-mbox.c create mode 100644 drivers/misc/aspeed-lpc-ctrl.c create mode 100644 include/uapi/linux/aspeed-lpc-ctrl.h -- 2.11.0 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
